From Bulbapedia, the community-driven Pokémon encyclopedia.
Blue (Japanese: グリーン Green) is a main character of Pokémon Origins and the rival of Red.
Blue made his first appearance in Pallet Town, where he met up with Red on his way to receive a Pokémon from Professor Oak. After racing each other on their way to Professor Oak's lab, Blue was given a Pokédex and chose a Squirtle, as it had a type-advantage to Red's Charmander. Afterward, he immediately left to start his journey to become the world's strongest Trainer. He met up with Red again near Viridian City and challenged his rival to a battle. Blue's Squirtle easily managed to dodge all of Charmander's attacks and deal heavy damage. Eventually, Red forfeited the match once he saw that Charmander was overwhelmed by Squirtle's power. Blue taunted Red for his loss and continued on his journey.
In File 2: Cubone, Blue decided to investigate the Pokémon Tower to get rid of Team Rocket and become a hero. However, once he got there, Blue encountered an actual ghost and ran away terrified of it. He bumped into Red and stated that they needed to get away. Red decided to stay and fight, so Blue continued upstairs, where he found and defeated a Team Rocket Grunt with Wartortle. Upon defeating the Grunt, he obtained a Silph Scope, which he gave to Red so that he could identify the ghost and stop it. Once Team Rocket had been driven out, Blue encountered Red leaving Lavender Town. He bragged about helping Red defeating Team Rocket, only for Red to point out that he was terrified the entire time.
In File 3: Giovanni, Blue helped Red rescue the Silph Co. vice-president from Team Rocket. Despite learning about what Team Rocket had done to the wild Pokémon they captured and the threat of the Master Ball they were trying to create, Blue showed no interest in helping the captured employees. Angered, Red forced Blue to help by telling him to inform the authorities of what had been going on while he went on and saved everyone else.
In File 4: Charizard, Blue had become the Champion. After defeating the Elite Four, Red faced Blue as his final challenge. Both parties battled hard, but Red eventually came out the victor. Professor Oak arrived to celebrate Red's victory and berated Blue for not putting his trust in his Pokémon. Sometime later, Red returned to Professor Oak's lab to evaluate his completed Pokédex. There, he found Blue, resting with heavy injuries that he got from battling a powerful Pokémon in Cerulean Cave.
Since the Pokémon he faced destroyed his Pokédex, any data it would have recorded was gone. Blue noticed that Red did not have the Pokémon in his Pokédex, meaning the one he faced was an undiscovered species. Despite Blue's warnings, Red decided to go and face the Pokémon, which he found out was named Mewtwo and caught after a long battle. Once Red returned from the battle, Blue angrily muttered to himself about his loss of his Champion title and Red's capture of Mewtwo.
Blue is very competitive towards Red and is constantly mocking him on his supposed inferiority towards him. This characteristic is apparent even outside of Pokémon battles, as shown in Lavender Town, where Blue decided to rescue Mr. Fuji before Red just to become the town hero instead of him. He also tends to have little interest in helping others if he considers his own goals more important, as shown during the Silph Co. incident, wanting to focus more on his goal of reaching the Pokémon League rather than saving imprisoned employees and Pokémon. Despite this, he was still shown to have a sense of goodness, helping Red in getting past the ghost Marowak and saving the Silph Co. vice-president.
Much like in the games, Blue has a lot of talent as a Pokémon Trainer, despite his young age, collecting all eight Badges and becoming the Champion before Red. Even Giovanni acknowledged that Blue's skills were far beyond anything he had ever previously seen. He's also a sore loser, being clearly unwilling to admit his loss to Red at the Pokémon League and feeling frustrated that Red managed to capture Mewtwo while he couldn't.
| Squirtle → Wartortle → Blastoise
| Blastoise is Blue's starter Pokémon. He chose it when it was a Squirtle after Red chose Charmander. Later, while Red was on his way to Viridian City to capture Nidoran♂, Squirtle battled Charmander and automatically won after Red forfeited the battle. Sometime before Blue went to Pokémon Tower, Squirtle evolved into Wartortle. Wartortle evolved into Blastoise sometime before he became the Champion of the Pokémon League. During the Pokémon League, Blastoise was the final Pokémon Blue used against Red where it was able to take out his Persian and Jolteon, but lost to Charizard after a long battle.
Blastoise's known moves are Tackle, Bubble, Bite, Skull Bash, and Hydro Pump.
|| File 1: Red
| Pidgeot was the first Pokémon Blue used in his League match against Red, where it went up against his Jolteon.
None of Pidgeot's moves are known.
|| File 4: Charizard
In File 4: Charizard, Blue mentioned that he had obtained 148 different species of Pokémon. It is unknown whether they are all Kanto-native species.
All Badges were obtained between File 1: Red and File 3: Giovanni.